Quantifying the domestic market in herbal medicine in Benin, West Africa

Herbal medicine markets are essential in understanding the importance of medicinal plants amongst a country's inhabitants. They are also instrumental in identifying plant species with resource management priorities. To document the diversity of the medicinal plant market in Benin (West Africa), to quantify the weight of traded species in order to evaluate their economic value, and to make a first assessment of their vulnerability for commercial extraction.We quantitatively surveyed 22 market stalls of 16 markets in the country's eight largest urban areas. We collected all plant (parts) following standard botanical methods and recorded uses, prices and local names, and weighed and counted the numbers of sales units.We recorded 307 medicinal products corresponding to ca. 283 species. Thirty-five species were encountered in at least 25% of the surveyed stalls, from which ten are locally endangered or red-listed by the IUCN. Examples of vulnerable species included Caesalpinia bonduc, which has been declared extinct in the wild but is largely cultivated in home gardens, and was exploited for its seeds, roots, and leaves, and Zanthoxylum zanthoxyloides which was harvested for its bark, roots, and leaves. Other top-selling fruits and seeds included red-listed species: Monodora myristica, Xylopia aethiopica, and Schrebera arborea. Top-selling woody plant parts included the roots of Sarcocephalus latifolius, Mondia whitei, and the barks of Khaya senegalensis and Pteleopsis suberosa. All but Sarcocephalus latifolius and Pteleopsis subersosa were species with some threat status. Plants sold at the market were mainly used for ritual purposes, women's health, and to treat malaria and its symptoms.Our results suggest that the domestic medicinal plant market in Benin is of substantial economic importance. A volume of approximately 655 metric tons worth 2.7 million USD is offered for sale annually. Traditional spiritual beliefs seem to be a major driving force behind the trade in herbal medicine.